Menopause is a natural life stage for women and hot flashes are experienced by an estimated 70-80% of menopausal women. Hot flashes are also experienced by breast cancer survivors and men undergoing androgen deprivation therapy. Research is ongoing to understand the fundamental physiology of hot flashes and other vasomotor symptoms, to explain the difference in symptom experience among individuals (including biological and cultural components) and ultimately to improve clinical management of hot flashes. Research studies have relied on subjective measures of symptoms (e.g. hot flash diaries) with a smaller number of researchers using the well established objective measure of sternal skin conductance. Current monitors for sternal skin conductance have drawbacks including the large weight and size of monitors, inability to collect and record data for adequate time periods, electrodes that need to be positioned and attached by trained personnel, and relatively high cost. Giner, Inc. will use its previous experience in wearable biomedical sensors to develop and test a miniature, wearable skin conductance monitor for hot flashes that measures skin temperature and skin conductance using novel electrodes and techniques. The final product will be a single unit combining electrodes, thermistor, skin conductance circuitry, microprocessor, memory, and battery with a serial port for downloading data. It will be suitable for long term (approximately 2weeks), comfortable and convenient wear on the sternum, neck or other areas of the body. The Phase I prototype monitor would be under 5 centimeters in diameter, under 1 centimeter in height and approximately 15-20 grams (around the weight of three U.S. quarter coins). In Phase II, the unit would be further refined and miniaturized with a goal of reducing the size/weight approximately by 30%. The Phase I prototype monitor will be evaluated and compared to existing monitoring technology with our clinical collaborators on 30 menopausal women. The proposed monitor would have an initial market as a research tool, which could possibly expand to a monitor for general clinical use. It is estimated that the monitor would cost less than $500 in the small quantities sold for research purposes, with lower, volume pricing possible in the future. The technologies developed in this project would also be applicable to other wearable, biomedical sensors under development by Giner, Inc.